Bag stacking apparatus



March 24, 1964 R. D. HAYES ET A].

BAG STACKING APPARATUS Original Filed June 25, 1957 5 Sheets-Sheet 1March 24, 1964 R. D. HAYES ETAL BAG STACKING APPARATUS 5 Sheets-Sheet 2Original Filed June 25, 1957 s m R T 05K A T Y R N MW E V ms m T RH. mm/mw RD March 24, 1964 R. D. HAYES ET AL 3,125,916

BAG STACKING APPARATUS Original Filed June 25, 1957 5 Sheets-Sheet 3[NVENTORS RICHARD HAYE$ DWIGHT E. CLARK fr)? dam -r'rvs R. D. HAYES ETAL BAG STACKING APPARATUS March 24, 1964 Original Filed June 25, 1957 5Sheets-Sheet 4 8 s s 0 0 m s w T a m M NM m m E H C m m |i: nwwml n n nu n nu- WD. r.. WA l nnuu l hn o T 0v 5:. R H I m 0 March 24, 1964 R. D.HAYES ETAL 3,125,916

BAG STACKING APPARATUS Original Filed June 25, 1957 5 Sheets-Sheet 5 WEBr/70 cm? BLADE i AIR cvuuosrz 12 E HANGER KNIFE INVEN'wRS RICHARD D.HAYES Dw'aHT E. CLARK ing horizontally, have had inherent disadvantages.

United States Patent 1 3,125,916 BAG STACKING APPARATUS Richard D.Hayes, Pittsford, and Dwight E. Clark,

Canandaigna, N.Y., assignors, by mesne assignments, to NationalDistilliers and Chemical orporation, a corporation of Virginia Originalapplication June 25, 1957, Ser. No. 667,771, now Patent No. 3,008,865,dated Nov. 14, 1961. Divided and this application Feb. 20, 1961, Ser.No. 92,435 4 Claims. (Cl. 83-96) This application is a division of mycopending application Serial No. 667,771, filed June 25, 1957, PatentNo. 3,008,865.

This invention relates to bag making, and more particularly to a methodand a machine for making contour or slope-shouldered garment bags fromrelatively flexible heat-sealable material such as polyethylene film.

Such bags are used by retail cleaning establishments and laundries andare commonly called pull-over garment bags due to the manner in whichthey are pulled down over a garment to place the garment in the bag.

It is a general aim of this invention to provide a method of making agarment bag of this type whereby the bags are manufactured at a veryhigh production rate. It is a related aim of this invention to providean improved bag making machine in which this method may be carried out.

Heretofore, exclusively mechanical systems for guiding and feeding a webof bag stock through the mechanisms of a bag making machine, andparticularly in arrangements where the bag is made while the web is mov-Ditficulties arise due to many causes, among these being the difficultyin grasping a web of relatively thin material for moving it in a precisemanner; friction resisting rapid passage of the web through themechanisms; lack of tautness in the web resulting from the inadequatesupport for the web during the bag making operations; and interferencewith the flow of the web following severing or heat sealing operationsdue to the Web sticking to the mechanisms or catching in parts of themachine.

Therefore, it is an object of this invention to overcome suchdisadvantages by carrying out the bag making operations in the machinewhile the web is guided and supported in a vertical path. By using thefeed system of this invention it is possible to maintain a higherproduction rate of finished bags for longer maintenance-free periods.The reduction in down time and uniformity of product results in reducedproduction costs.

A further object is to provide apparatus for stacking bags as they aremade in the machine which is eifective ,to stack the output of themachine in an orderly, efiicient manner.

Further objects will appear from the following description taken inconnection with the accompanying drawings, wherein:

FIGURE 1 is a perspective view of a finished gusseted garment bagconstructed by use of the machine and in accordance with the method ofthis invention;

FIG. 2 is a horizontal sectional view of the bag taken in the plane oflines 22 of FIGURE 1;

FIG. 3 is a diagrammatic view showing the path of j the material throughthe machine in making bags;

FIG. 4 is a view in side elevation of the bag making machine; 1

FIG. 5 is a top plan view of the bag making machine;

FIG. 6 is a transverse vertical sectional view showing the fly stackerapparatus taken substantially in the plane of lines 15'15 of FIG. 4;

FIG. 7' is a schematic view of the machine drive; and

FIG. 8 is a fragmentary horizontal sectional view show- .ing the drivefor the conveyors.

3,125,916 Patented Mar. 24, 1964 While the invention is susceptible ofvarious modifications and alternative constructions, a preferredembodiment thereof has been shown in the drawings and will be describedbelow in detail. It should be understood, however, that there is nointention to limit the invention to the specific form disclosed, but, onthe contrary, the intention is to cover all modifications, alternativeconstructions and equivalents falling within the spirit and scope of theinvention as expressed in the appended claims.

General Machine Organization Turning now to the drawings, andparticularly to FIG- URES 1-4, the bag making machine 20 includes aframing structure divided into an upper section 21 and a lower section22. A web of bag stock (FIGS. 2, 3) is drawn continuously into themachine from a supply roll or directly from an extruder and enters themachine at the upper left-hand side of the machine as viewed in FIG. 4,at the forward end of the machine.

in accordance with the invention, the web is drawn over a series ofrollers into a vertical path and fed downwardly into a machine headhaving heat sealing and ma terial severing elements for formingdownwardly converging seams defining the neck of the bags and forcutting the material into finished bags. In the exemplary form of theinvention illustrated, referring particularly to FIGS. 3 and 4, themachine head 25 is positioned substantially centrally of the machine andjust beneath the upper horizontal rails 26 of the machine framestructure. The bags emerge from the head inverted, with the contoursealed end or neck 27 (FIG. 1) of the bag hanging down. The finished bagis then severed from the web leaving the bottom 23 of the bag open. Atthe instant of delivery, in keeping with the invention, a fly stacker 29takes the bag and lays it flat on a receiving platform.

The web moves intermittently through the machine head so that the heatsealing and severing operations may be carried out while the Web isstopped. For moving the web through the machine, draw rolls 31, 32 areused which are positioned above the machine head and deliver the web toit. Referring to FIGS. 3-5, it will be seen that the horizontal toprails 26 of the upper section 21 of the machine support guide rollers 33over which the web is trained as it is led from a dancer roll assembly36 at the receiving end of the machine to the draw rolls. The web duringthis period of travel also passes over an elestric eye scanner 37 whichthrough a control to be later described, synchronizes the operation ofthe machine head 25 with printed matter which has been previously placedon the web.

Material Feeding Apparatus In accordance with the present invention, theweb of bag stock is positively drawn into the machine by mechanicalmeans, and is moved through the machine to the stacking apparatus forthe finished bags, and supported during the bag making operations by anair feed system.

Due to the fragility and limpness characterizing certain types ofplastic film which may be made into bags by this machine, for examplepolyethylene film of a thickness approximating 0.5 mil, substantialproblems are encountered in supporting the film for the heat sealing andsevering operations and in guiding and feeding the film through thevarious mechanisms. In the machine illustrated, at a production rate ofup to 200 finished bags per minute, the film is maintained in alinementduring processing, and the finished bags are taken as they emerge fromthe machine and stacked in an orderly, efficient manner.

As depicted diagrammatically in FIG. 3, the web is drawn into themachine passing over a dancer roll assembly 36 at the forward end of themachine and over the scanner assembly 37.

Introduction of Web to Machine Head For drawing the Web into the machineand up to the point of entrance into the machine head 25, grooved drawrolls 31, 3 2 of resilient material such as rubber are used (FIG. 3),the peripheral contact between the rolls caused by compression springsproviding means for applying proper tension to feed the web evenlythrough the machine at the required speed. These draw rolls 31, 32 aresupported in bearings mounted by means of the spaced end brackets boltedto the framing members of the upper frame section 21. The dancerassembly 36 is composed of two idler rolls 101, 102 (FIG. 4) mounted atthe ends of parallel, pivotally supported arms 103. The motion of theweb through the machine head 25 is intermittent in order that the heatsealing and cut-off operations may be carried out in the machine head onthe web while the web is stopped. The web from a continuous, even supplyas it is received, is taken up and fed out in an intermittent movementby the dancer roll assembly 36. For driving the grooved draw rolls 31,32 intermittently in a direction to draw the web into the machine, adrive is employed (FIGS. 4, including a variable speed motor 105 andgear reducer 106, a crank 107, and a rack 108 and pinion 109 driven fromthe crank 107 whereby reciprocatory motion is imparted to the pinion109. The rack 108 is mounted at the drive end on a fulcrum pin 109'fastened to a block 110 slidably mounted in the crank arm casting. Atthe pinion, the rack is slidably mounted between brackets 111 whichsupport rollers 112 which engage the rack and apply pressure to maintainthe rack and pinion teeth in driving engagement with load conditions.

Reciprocatory motion of the pinion shaft 115 is trans mitted throughgears 116 to an intermediate shaft 117 on which means are mounted fortranslating the reciprocartory motion to intermittent uni-directionalmotion. In the present exemplary illustration of the invention, thismeans comprises an electric clutch and brake 118, for example, a Warnerclutch brake size 500, actuated through the use of the scanner assembly37 and appropriate microswitches and cams. It will be understood by aman skilled in the art that equivalent arrangements such as an ordinaryover-running clutch may be substituted to obtain this same result.Herein by means of such control instrumentalities the clutch is engagedduring a forward stroke of the rack and the brake engaged during thereturn stroke. This causes the intermediate shaft 117 to rotate in onedirection as the rack 108 moves torward, and to remain stationary as therack returns. It will be understood that during the periods that theintermediate shaft 117 remains stationary, the mechanisms of the machinehead operate to seal the bag and sever the material so that the finishedbag is cut off and delivered to the stacking apparatus. For transmittingthe intermittent uni-directional motion to the web, a sprocket drive 120is employed for connecting the intermediate drive shaft 117 and the drawrolls 31, 32. By means of the scanner assembly 37 which registers uponan eye mark on the film, and a brake and clutch control (not shown) asconnected to the scanner, the operation of the brakeclutch 118 issynchronized with the print location on the film. Thusly, printed matterpreviously placed on the continuous web of bag stock appears properlylocated on the finished bags.

For adjusting the length of bags made on the machine, means are providedfor controlling the number of revolutions of the draw rolls 31, 32 percycle of the intermittent motion deriving mechanism, and thus the lengthof the film drawn by the rolls per cycle. As shown in FIG. 4, for thispurpose means are provided for varying the stroke of the crank 107 by anadjustable screw 123 which moves the block 110 slidably mounted in thecrank arm casting.

This block supports the fulcrum pin 109' on which the drive end of therack 108 is pivoted. For adjusting the stroke of the crank 107 while themachine is operating, a control rod terminating in a readily accessibleknob 124 is provided for manipulating the adjustable screw as by movinga pin carried by the control rod into position to be contacted by atoothed wheel 126 on the screw as the crank arm rotates.

For a disclosure and description of the details of the machine head 25,reference may be made to copending application 667,77 1 of which this"application is a division.

Mechanical and Air Feeding of Web In keeping with the present invention,a combined mechanical and air feed is used for guiding the web into themachine head 25, conveying the web through the head which involvesstripping the bag stock from the heat-sealing bars, and moving the limp,flimsy material vertically downwardly so that it is suspended evenlyfrom the machine to be taken by the stacking mechanism.

After the completion of a heat-sealing operation, the platens 40, 41open to allow the sealed neck of the partially made bag to be fedvertically downwardly so that the continuous web may be severed by theshear blades 42, 43 into bag lengths to form the finished bags. In orderto deliver the web downwardly into the free, open space below the head25, air manifolds 155, 156 mounted on the opposite sides of the path ofthe web are used for directing currents defining an air gate directlybelow the machine head 25. The currents of air from the manifolds mergebelow the head allowing the web to remain flat as it moves verticallydownwardly and to hang suspended during the period of operation of themachine head. Considerable air turbulence is created in the lowersection of the machine frame below the head during the operation of themachine, and in the present case particularly by reason of theconstruction of the fly stacker which will be described hereinafter.This air turbulence is counteracted by the currents of air directed fromthe air manifolds forming this air gate, so that the web flows evenlyand smoothly to the stacker. Furthermore, because the sealed end of theweb is down, air is not picked up to balloon the tube.

Referring to FIG. 3, as shown the air manifolds 155, 156 compriseparallel tubes mounted by means of blackets to the platens below themachine head on each side of the path of the web. Spaced openingsdirecting air downwardly and angled so that the currents of air mergeserve to control the air flow in the manner desired. under pressure issupplied to the manifolds by service lines.

Fly Stacker For receiving the finished bags as they emerge from themachine head 25 in a flat condition and lying substantially in avertical plane, in carrying out the invention an oscillatable flystacker 29 is provided which is operated in time with the delivery ofthe bags so that the stacker takes the bags in the vertical position andlays them flat alternately upon opposite horizontal platforms. Thebaghangs poised after being severed, and is supported flat and on anevenkeel by the air feed system, and is then taken by the fly stacker.

Referring peraticularly to FIGS. 3, 4, and 6, the fly stacker 29 asthere shown includes an open, substantially rectangular screen 160 madeup of parallel bars 161 of light but strong material, forexample,aluminum, with end members 162 securing the bars together preferablymade of fiberglas'tubing. The open framing making up the screen iscovered by a large mesh netting 163 like tennis netting. For mountingand drive purposes, the screen 160 is supported by a shaft 164 which iscarried in suitably positioned hearings in the machine frame. This shaftis positioned substantially in the plane of delivery of the bags. Adrive 165 connected to this mount-- ing shaft supplies oscillatorymotion to drive the shaft in a manner that causes the stacker screen 160to move between opposite horizontal positions (FIG. 3) through avertical position where the finished bag is taken upon delivery againstthe screen on both forward and return strokes. Oscillatory motion fordriving the fly stacker screen is obtained from a rack and pinionreciprocatory motion deriving mechanism 166 (FIG. 5) located on theupper frame section 21, and driven in synchronism with the elements ofthe machine head 25, from the main drive motor 105 through the outputshaft 133 of the gear reducer 106, the first sprocket drive 131, and thesecondary drive shaft 167. This reciprocatory motion deriving mechanism166 is like the similar mechanism including the rack 8 and pinion 109used in the drive for the draw rolls 31, 32. While different receivingarrangements for the finished bags may be employed, in the presentinstance, horizontal platforms are provided by conveyors 168, 169 whichare operated in timed sequence with the stacker screen 160 by means of asprocket drive 170 which connects the mounting shaft 164 of the screenand the conveyor shafts, respectively.

S ummtzry of Operation While the operation of the machine in makingfinished bags will be evident from the preceding description, referr-ingto the schematic view, FIG. 3, showing the path of the web through themachine, and FIG. 7 showing the drive, a complete cycle of operationwill be described.

To start up the machine, the machine control (not shown) is energizedcausing the heat-seal elements to heat up (connections not shown) andair to be supplied to the air manifolds of the air feed system. The bagstock, for example, polyethylene film, is then manually threaded throughthe dancer roll assembly 36 and into the draw rolls 31, 32. The machineis preferably started with the stacker screen 160 in the down position,and thus with the machine head platens 4t 41 and cut-off knives 42, 43open. By the use of an auxiliary air motor 171, the draw rolls 31, 32are operated without the platens 4t), 41 being operated so that the webis drawn freely through the machine head 25. For satisfactory operationthe web should be wrinkle free and with a slight tension existingbetween the dancer roll assembly 36 and the draw rolls 31, 32. Onceadjustments have been made to obtain proper web flow, then the maindrive may be started, to operate the machine head 25 and stackingapparatus 29.

A full cycle of operation begins with the draw rolls 31, 32 stopping andthe platens 40', 41 of the machine head 25 closing together to clamp theweb and form the downwardly converging seams defining the neck of thebag (FIG. '1). During this period the dancer roll assembly 36 takes upthe momentary slack and maintains tension in the web as it is fedcontinuously from the extruder or supply roll. As the platens 40, 41come together, the hanger slot blade is actuated to form the slot '70for the clothes hanger. During this operation the heat seal bars ond padcarried by the forward and rear platens 40, 47 respectively, give addedsupport for the web so that the hanger slot blade upon actuating forms aclean cut in the film.

Likewise, as the platens 40, 41 come together, the cutoff knives 42, 43for severing the web are operated. Due to the angular relation of theshearing edges the severing begins at one side of the web and movesacross the width of the web. With proper timing these cut-ofl knives 42,43 commence to out just prior to the instant the hanger slot knife isactuated. This action whereby the cut-off knives shear the web, alsolends support to the material so that the hanger slot knife can pierceand form a clean cut.

The heat sealing elements borne by the platens operate to form therequired seams and also as a hot knife cutoff, to sever the web alongthe edges of the seams. The chip which remains between the convergingseams and 6 the square cut-off is cleared from the machine head 25 bythe chip ejector blade. This blade is operated when the cut-off knives 42, 43 have completed the severing operation. Moreover, to the completionof the cut-off operation, the platens 40, 41 of the machine head 25 opento release the web and the draw rolls 31, 32 begin again to feed.

The severing operation performed by the cut-off knives 42, 43 separatesthe finished bags from the continuous web. These finished bags are takenat the instant the material is severed, by the fly stacker screen 160,and placed on platforms formed by conveyors 168, 169 positioned for thatpurpse. The operation of the fly stacker 29 is such that the finishedbags are received on both the fonward and return strokes, and a counter174 operated from the mounting shaft 164 for the stacker screen iseffective to count out the finished bags.

We claim:

1. A stacking apparatus for bags of flexible, limp, film material, saidbags being delivered to the stacking apparatus in a flat condition andlying in a substantially vertical plane, horizontal bag stack receivingplatforms on each side of the plane of delivery of the bags, a flystacker including a large mesh screen mounted between said platform, andmeans for oscillating said fly stacker to take said bags in the verticalposition upon delivery and lay them flat alternately on said platforms,said screen being movable through the vertical plane of delivery of thebags to substantially horizontal position in engagement with the top ofa stack of bags on one of said platforms.

2. A stacking apparatus for bags of flexible, limp, film material, saidbags being delivered to the stacking apparatus in a flat condition andlying in a substantially vertical plane, comprising, in combination,horizontal bag stack receiving platforms on each side of the plane ofdelivery of the bags, a fly stacker including a frame and an open meshscreen on said frame mounted between said plat-forms, means mountingsaid screen for oscillatory movement to pass through the vertical planeof delivery of the bags to a substantially horizontal position inengagement with the top of a stack of bags on one of said platforms, andmeans for timing the oscillation of said fly stacker screen with thedelivery of bags so that said fly stacker takes said bags in thevertical position upon delivery and lays them flat alternately on saidplatforms.

3. A stacking apparatus for bags of flexible, limp, film material, saidbags being delivered to the stacking ap paratus in a flat condition andlying in a substantially vertical plane, movable horizontal bag stackreceiving platforms on each side of the plane of delivery of the bags, afly stacker between said platforms, said fly stacker including a frameand an open mesh screen on said frame mounted for oscillation between asubstantial horizontal position in engagement with the top of a stack ofbags on one of said platforms and arranged to pass through the verticalplane of delivery of the bags, and means for timing the oscillation ofsaid fly stacker with the delivery of bags so that said fly stackertakes said bags in the vertical position upon delivery and lays themflat alternately on said platforms, said bags being retained by airpressure against said screen.

4. In apparatus for stacking bags out from a web of relatively flexiblefilm material, means for feeding the material web into a vertical plane,substantially horizontal bag receiving means on each side of said plane,an oscill-atable fly stacker mounted between said bag receiving meansincluding an open mesh screen movable in the course of forward andreturn strokes through an upright position in said vertical plane, saidscreen being movable to a substantially horizontal position inengagement with the top of a stack of bags on one of said platforms, andmeans immediately above said fly stacker screen in the upright positionof the latter for cutting the material web transversely into bags intime with the oscillation of said screen so that said screen takes a bagwhen in the References Cited in the file of this patent UNITED STATESPATENTS Luhn June 12, 1 894 8 Cottrell Sept. 25, 1906 Pancoast Apr. 13,1909 Banze'tt'et a 1 Nov. 24, 1914 Sites Oct. 20, 194-2 Lei-bold Aug.18, 1959

1. A STACKING APPARATUS FOR BAGS OF FLEXIBLE, LIMP, FILM MATERIAL, SAIDBAGS BEING DELIVERED TO THE STACKING APPARATUS IN A FLAT CONDITION ANDLYING IN A SUBSTANTIALLY VERTICAL PLANE, HORIZONTAL BAG STACK RECEIVINGPLATFORMS ON EACH SIDE OF THE PLANE OF DELIVERY OF THE BAGS, A FLYSTACKER INCLUDING A LARGE MESH SCREEN MOUNTED BETWEEN SAID PLATFORM, ANDMEANS FOR OSCILLATING SAID FLY STACKER